(Adds comment from machinists' union; context on where airline
now performs its heavy maintenance)

By Allison Lampert

MONTREAL Jan 5 (Reuters) - Air Canada said on
Tuesday it is seeking to appeal to the country's highest court a
decision last year ordering the airline to keep heavy
maintenance operations in Montreal.

In November, the Quebec Court of Appeal ruled against the
country's largest carrier, upholding a lower court's 2013
decision that Air Canada must keep the operations in Montreal.

"We are seeking to appeal to the Supreme Court of Canada the
Quebec Court of Appeal's decision in order to provide clarity on
important issues it raises," Air Canada spokeswoman Isabelle
Arthur wrote in an email. "As this is before the court, we have
nothing to add to our filing."

The government of the predominantly French-speaking province
argued that Air Canada breached its legal obligations to keep
heavy maintenance operations in the country after the carrier
closed a facility in Montreal in 2012.

The facility was operated by the former Aveos Fleet
Performance, once an important Air Canada contractor. In 2012
Aveos obtained creditor protection and laid off its 2,600
Canadian employees, including about 1,700 workers in Montreal.

The Air Canada Public Participation Act, the law that has
governed Air Canada's operations since its 1988 privatization,
says the airline must maintain overhaul centers in Quebec,
Manitoba and Ontario.

The appeals court said Air Canada was contravening the act
by not maintaining an aircraft overhaul operations in Montreal.
Continued...